Domestic violence act 2005

Hi, My brother got married in 2014. They had a baby in Oct 2016. Both, my brother and his wife always had issues and verbal arguments frequently since they got married as he was asked to take baptism to get married and later on was coerced by her family to visit their church every Sunday against his will which worsened the situation and their relationship. In the moment of heat, he had slapped her once post which he and my parents were physically attacked and verbally abused by her parents, brother, and sister. However, they agreed their mistake for hurting my brother and parents and apologized. After a month after all this happened, they again had an argument wherein she supported whatever her parents did to my brother and my parents and didn't have 1% remorse for what her family had done and agreed to leave our house along with her baby. She left the house and went along with her dad to her maternal house though my brother had asked her to stay with us/ separately in a rented house if she's uncomfortable staying with parents, me and my wife. Today December 11, 2018, we got a letter from magistrate saying she has filed a case of domestic violence u/s. 13(1) on Nov 14, 2018. However, we got the letter today asking us to present ourselves in front of the magistrate tomorrow morning at 10:30 am. What do you think needs to be done or can be done? Your advises will be greately appreciated by me and my family and could be of great help to us to face such unforseen situation.